The following problem occurs when i try to start my friend's windows 7 system

when the system starts he gets the following error :

PXE:E61 Media test failure ,check cables press any key to continue

when i pressed "Esc" or any other key it repeats the error;

when i Google the error there were answers which recommends me to check whether the media boots with network medium,i checked bios and disabled network boot and restarted the machine but the error continues;

the following things i made before posting here

1.changed bios setting (disabled network boot)

2.checked hard disk ports(whether its properly assembled)

3.i tried to boot from DVD but the windows exited with additional message DVD ROM failure,
then i replaced my DVD drive(its working fine upto now in my system_ and tried to boot the same error continues

another horrible thing is in bios i cant find the hard drive listed but i can boot and display the above mentioned error

i doesn't like to format the machine** ,any suggestions to overcome this error and make regular booting;

I was getting the same error. I noticed that the screws securing the hard drive weren't reaching the drive. Crucial included a rectangular plastic "spacer". I placed the spacer in the hard drive tray, put the drive in the tray and slipped it back in the laptop. The screws secured the drive and the computer booted perfectly.